Fluid flow control system



May 26, 1936. w. GREEN 2,041,922

I FLUID FLOW CONTROL SYSTEM 4 Filed June 15, 1955 2 Sheets-Sheet 1 fizz/65151:

y 1936- w. H. GREEN V 4 FLUID FLOW CONTROL SYSTEM Filed June 15, 1955 2 Sheets-Sheet 2 Patented May 26, 1936 PATENT OFFICE FLUID FLOW CONTROL SYSTEM Walter H. Green, Chicago, Ill., assignor. to General Zeolite 00., Chicago, 111., a corporation of Illinois Application June13, 1935, Serial No. 26,458

20 Claims. (Cl. 137-1525) This invention relates to apparatus for the control of fiuid flow and as a means thereto to the governing or positioning of a valve or valves and it also includes means for indicating the flow. The flow that is subject to control may be unrelated to any other or it may be one of a group or series that are to be governed together. It is intended also that when there are a group of flows theymay all be increased or decreased together through some common setting device or that some one or more of them may be separated from such common device and set separately. One particular object is to provide that when a flow is shut off or when it is to be reset at some i new value the adjustment or shift of flow shall take place relatively slowly so that there will be no surges or shocks. While it is contemplated that in the great majority of cases the control will be to the end of maintaining a fixed flow of some set volume per unit of time it will be apparent that the flow or flows can be controlled relative to something else, say to some other flow or a level, by suitable connection.

One particular object is to provide an improved method and means for controlling the efliuent flow from a water treating unit such as a filter bed in a filter plant; and because of this and because most of such plants employ a plurality of such beds, the efiluent flows from which are usually to be held in unison, and because furthermore it is commonly desirable in such plants to set the rate of flow for all units from a common point, this invention will be described in connection with such a plant. As, is well known a typical filter plant of that sort comprises a plm'ality of filter beds in open-top containers arranged in a row or rows on one or both sides of an operating floor and are provided with the necessary piping and valves for directing and controlling the several flows occurring during operation and ordinarily with gauges for indicating various functions. Experience has long ago shown that during the filtering phase the rate of flow should be held at I an even rate and consequently in such plants each bed is commonly provided in the efiluent line with what is called a rate of flow controller, by which the rate can be controlled. There are a number of makes or types of such controllers on the market which vary considerably in some fea-\ tures but which have in common certain characteristics. All that are in common use derive a pressure differential from the flow and use this in some way to position a valve to control the flow at the set rate and have some means by which the rate may be set at difierent values as desired,

While it is desirable to be able to set each controller without relation to the others in such a plant it is also desirable and especially so when a plant comprises a considerable number of units, to be ableto revise the setting of all in unison from a common point or setter so as to increase or decrease the delivery of all units together to agree with demand. Various ways have heretofore been used for setting the flow on a controller, usually involving opposing the derived differential to a weight or pressure that could be varied. When means have hitherto been proposed for changing or governing the setting of several controllers from a common point these have correspondingly involved means for shifting or varying the weight or changing the opposing pressure. In my application, Serial No. 616,440,

which has now resulted in Patent No. 2,011,049, an

the way of increase of flow and particularly so when of considerable degree. One purpose of the present invention is to provide for changing this setting of an individual controller, or group thereof in a way such that while the shifting of the part that will result in setting to this new rate may be quickly made as is ordinarily most convenient, yet the rerating of the controller or controllers so initiated will take place slowly at a governed speed.

In the accompanying drawings Fig. 1 is a diagrammatic and perspective view comprising a filter bed which may be one of a group or series forming a complete plant as referred to above, and having a controller in the efiluent line with 5 my improved setting and governing means associated therewith. v

' Fig. 2 is a sectional view on line i-t of Fig. i. Fig. 3 is a diagrammatic view in perspective of an impulse transmitting device cooperating with the solenoids of Fig. 2.

In Fig. 1, l is a sheave free to move on'shait i which is held stationary in supports to and 2b, 3 is a manometer connected to a Venturi. tube ta. In one leg of the manometer rides a float being free to rotate upon stationary shaft 2.-

|0, rotates Clutch 9 is mounted upon sleeve therewith, and is longitudinally movable thereon. Gears II and I2 are free to rotate on sleeve I0 and are prevented from movement longitudinally along the sleeve by means of set collars not shown. Gears I3 and I4 and sprocket I5 are fixed to shaft l6, free to rotate in bearings I1 and Ila. Sprocket I5 is connected by a chain or cable I8 to sprocket I9 mounted on the shaft 20 of a reversible motor 2|. The gears II and I3 also I2 and I4 are so chosen as to cause gear I2, which rotates in a clockwise direction when viewed facing the pointer 6, to rotate at a slower rate than gear II which moves in a counterclockwise direction. This is done because I2 is used when the rate of flow is being increased .and II when it is being decreased and it is ordinarily better to increase the flow at a slower rate than it may be decreased. By change of these gears or the ratio of sprockets l5 and I9 the rate of shift may be adjusted to suit conditions.

The clutch 9 has teeth 9a, not seen, on one face and teeth 9b on the other face, 9a and 9b being oppositely disposed as to rotational direction of engagement. The gear l2 has teeth I2a which are adapted to register with 9a and gear II has teeth Ila, not seen, adapted to register with teeth 9b. Teeth 9b and Ila are normally held in engagement by means of spring |0I and bell-crank M2. The free end of bell-crank I02 is attached to the plunger I03 of solenoid I04.

Mounted on shaft 2 and free to rotate thereon is a sleeve 23. Fixed on this sleeve 23 are a pointer member 24, ratchet 25 and ratchet 26. The teeth on ratchets 25 and 26 look in opposite directions. Adapted to engage teeth on atchet 26 is a pawl 26a, pivotally mounted on lever 21, and adapted to engage teeth on ratchet 25 is a pawl 25a pivotally mounted on lever 28. One end of lever 21 is pivoted about shaft 2, the other end engaging the plunger 29 of a solenoid 29a. Similarly, one end of lever 28 is pivoted about sleeve 23, the other end engaging the plunger 30 of a solenoid 30a.

Mounted on sheave I and insulated therefrom is a contact arm 3| adapted to contact with either of the conducting segments 32 and 33 which are mounted on disc 8 and insulated therefrom. On pointer 24 and insulated therefrom is the contact arm 34 adapted to contact with either of the conducting segments 35 and 36 also mounted on disc 6 and insulated therefrom.

In Fig. 1, 40 is a filter bed, 4| is a valve, usually of the hydraulically operated type, 30 is a Venturi tube, 42 is a regulating valve through the outlet 43a of which the filtered water is carried to a point of storage or use. During operation of the filter, valve 4| is normally wide open and when the filter is put out of service, as for back-washing, the valve 4| is closed. Valve 4| is caused to open or close by means of a lever ||0 operating a four-way cook or pilot valve, not shown, in the well known manner. When V cury on which float 4 rides will rise.

the lever H0 is in the position to open valve 4| the contacts 2 and N3 of a switch are bridged; when the lever H0 is in the valve closing or closed position contacts 4 and 5 are bridged.

The head available for causing flow from the filter usually continually decreases during the operation of the filter because of the clogging up of the filter bed by deposited sediment as filtration progresses. As the rate of flow through the bed is to be kept at a substantially constant rate, the regulating valve 42 is employed to afford a variable resistance to the passage of water which may be adjusted inversely to the resistance of the filter bed. The variable restrictionin the regulating valve is provided by a valve seat 42a and a movable plunger 43 attached to flexible diaphragm 44. This diaphragm is subjected on one side to the pressure in compartment 46, this pressure being subject to controlled variations by either admitting. water under pressure through pipe 41, solenoid operated valve 43 and pipe 49, or permitting water to pass out through pipes 49 and 50 and solenoid operated valve 5| to any suitable point of discharge.

In Fig. 1, the pointer 24 is shown as having been set by means vof knob 52 to a position on the scale representing some pre-determined desired rate of flow and the figure shows the condition of the various parts while this rate of flow is being maintained. If a decrease from the rate'should occur through the fiuid conducting system that includes venturi 3a the pressure differential will decrease and level of the mer- This will cause a counter-clockwise movement of sheave and contact arm 3| will move onto contact ring 33. Electric current will now flow from terminal 52 of source of E. M. F. 5311, through conductor 53 to contact 3|, to ring 33, conductor 54, solenoid 55 of valve 5|, through conductor 56 to terminal 51 of 53a. Solenoid 55 will therefore be energized and open valve 5| which will permit passage of water from compartment '46 to waste allowing diaphragm 44 and hence plunger 43 to move so as to increase the opening between plunger 43 and valve seat 421:. This will cause an increase of flow through the fluid conducting .system with a consequent gradual lowering of the mercury level whereon float 4 rides and also a motion of contact 3| (now on ring 33) toward the neutral point. When the contact 3| reaches the neutral point (which is its original position' corresponding to the desired rate of flow) the circuit of solenoid 55 will be broken and valve 5| will close, holding the flow at the predetermined rate.

Conversely if there should be' an increase of flow through the fluid conducting system, the float 4 will fall, causing contact 3| to move onto ring 32 of disc 8. Electric current will now flow from terminal 52 of source of E. M. F. 53a through conductor 53, contact 3|, ring 32, conductor 60, solenoid 59 and conductor 56 to terminal 51. Solenoid 59 will then be energized, opening valve 48 allowing'pressure water from 41 to enter compartment 46 moving diaphragm 44 and plunger 43 toward seat 42a and thus diminishing the flow. This is accompanied by a rise of the float 4 and movement of contact 3| toward the neutral point on disc 8. When the neutra1 point is reached, the circuit of solenoid 59 of valve 49 is broken and valve 48 will close holding the flow at a predetermined rate.

Should it be desired to increase the set rate of flow, the pointer 24 may be moved by means of knob 52 to a position on .the scale I indicating the desired higher rate. The contact pin 34 will now be on ring 36 of disc 0 and an electric circuit will be established between source of E. M. F. 65 and coil A of motor 2| as follows: From terminal SI of 65, conductor I (shown broken) contact 34, ring 36, conductor 62, contacts H2 and H3, conductor 62a, coil A' of motor 2| to terminal 63 of 65. A complete electrical circuit will also be established through solenoid I04 operating bellcrank I02, as follows: From terminal 6i of E. M.

F. 65, conductor I60, contact 34, ring 36, conductor 62, contacts H2 and H3, conductors 62a and M51 solenoid I04, conductor I04a to terminal 63 of 65. This will energize solenoid I04 which through bell-crank I02 will move the clutch into engagement with teethof gear I2. At the same time motor shaft 20 will start to rotate in a counterclockwise direction (facing shaft end) and through sprocket I3, chain I8, sprocket I5, gears I5 and I2 and clutch 3 will cause disc 3 to rotate in a clockwise direction until ring 36 leaves contact 35, when thecirCuits of the motor 3i and solenoid I05 will be broken and clutch 9 returned to engagement with teeth in gear II. In the meantime ring 33 will have moved onto contact pin 3i, establishing the circuit throughsolenoid 55 of valve III which will have opened thechamber 53 to waste, thereby permitting a greater opening between plunger 53 and seat 530. and

therefore a greater rate of fluid flow through the current will travel through conductor I53, contact pin 35, ring 35, conductor 33 (shown broken) to coil B of motor 3i and to terminal 33 of 35. The motor shaft 33 will now rotate in a clockwise direction and by means of sprocket I3, chain I3, sprocket I5, gears I3 and II and clutch 3 will cause disc 3 to rotate in a counter-clockwise direction until ring 35 leaves contact 35 when the motor 3i will stop. In the meantime contact pin 3i will be on ring 33 whereupon a circuit will have been established through solenoid 53 of valve 53 thereby causing movement of diaphragm 55 and plunger 53 toward seat 53a, restricting the how. When the predetermined rate of flow is reached contact pin 35 will leave ring 33, deenergizing solenoid 53 and closing valve 53, thereby establishing the newly set rate of fiow. as before described.

In filtration plants employing a plurality of filter beds it is as above referred to convenient to be able to set the rate of flow for the several filters from a central location remotely located from the mechanism above described. Thismay be accomplished as follows:

Referring to Fig. 2: When the solenoids 39a and 33a are de-energized the levers 3I and 33 are held against stops Na and 3302 by springs 3Ib and 33b respectively. Pawl 33a is kept out of engagement with ratchet 33 by spring 35b and against stationary stop 33c. Pawl 35a is kept out of engagement with ratchet 35 by spring 35b and against stationary stop 25c. If now, solenoid 33a. should be energized the lever 35 and its pawl 33a will move downward until the end of 21 strikes the end of the solenoid, which serves as a stop, this movement corresponding to the angle of one tooth on ratchet 25. The extended portion 26d of pawl 26a will cause a forward movement of the lower end of pawl 26a causing it to mesh with the ratchet 26 and hence a clockwise movement of pointer 24 of a predetermined angular magnitude, since botliratchets 25 and 26 andpointer 24 are all mounted on sleeve 23. Each energizing impulse of solenoid 29a will thus produce equal angu-1 lar movements of pointer 24 in a. clockwise dire'ction. Similarly each impulse of solenoid 30 will produce similar angular movements of pointer 24 but in a counter-clockwise direction. It is therefore seen that the position of pointer 25 may be changed and hence the rate for which the controller is to be set may be varied a desired amount either upward or downward, by energizing solenoid 39a or 30a the proper number of times. As indicated in Fig. 2 the ratchets 25 and 36 may be segmental, having a number oi teeth corresponding to the working range and thus avoid jamming or over-setting.

The wiring to solenoids 35a and 30a is not shown in Fig. 2 and may be made in any convenient manner according to common practice. As a matter of convenience however, and particularly 5 when it is desired to set a number of controllers from a common pointit is desirable to provide mechanism for this and one form thereof is shown in Fig. 3. In Fig. 3, 33' and 33' represent solenoids 39a'and 30a of a'plurality of mechanisms as shown in Fig. 2, each of which forms part of a mechanism as shown in Fig. 1, each with a filter bed and so forming a multiple unit plant, associated with a common setting device, remotely'located at a central control station. A reversible motor I33 drives the friction disc III through shaft H3 'and thus the larger disc II3 on shaft II5. Disc III is shiftable on disc III3 by lever II5 so as to provide for changing speed of shaft 5 I5. Disc I3 is fixedly attached to shaft II5. Shaft II5 is free to rotate in the bearings I5 and Mia. A pointer I5, to which is attached contact 35 insulated therefrom, and a knob I3, is free to rotate about the outside of sleeve I3, which is part of the bearing I5. Pointer I5 registers with dial II, calibrated as desired as in rates of flow. 0n the periphery of disc I3 are the two rings I3 and 33,

which are insulated from 113 and from each other. Also mounted on disc I3 and insulated therefrom are a plurality of segments 3i electrically communicating with one another.

In the position shown in Fig. 3 contact M is out of contact with rings I3 and 30, therefore both electric circuits comprising the motor I33, E. M. F.

33 and conductors 33 and 35 are b oken, as are also the circuits comprising solenoids 33' and 39',

conductors 35, 35, 3I, 33, 33, contact 35 and segwill then rotate in the direction to drive disc I3 in a'counter-clockwise direction until contact 35 will move from 03 ring I3 to the neutral point between rings I3 and 33, whereupon the motor I0 and disc I3 will stop. Disc I3 in assuming its new position will havecaus'edcontact 95 to contact with the segments I8I as they pass thereunder, thereby energizing the circuit of solenoids 29' a predetermined number of times as follows: From terminal 98 of E. M. F, 82 to conductor 89, segments I8I, contact 95, conductors 88 and 88, solenoids 28', conductors 81 and 83, ring I9, contact 8|, conductor 83 to terminal 8| of 82.

If it is desired to decrease the rate of flow of the remotely located filters, pointer 15 is moved in the opposite direction. Contact pin 8| will now contact with ring 88 establishing a circuit through 'winding B of motor III as follows: From terminal circuit being as follows: Terminal 88 of E. M. F.

82, conductor 89, segments |8|, contact 95, conductor 88, solenoids 30', conductors 85 and 84, ring 80, contact 8|, conductor 93 and back to terminal 8| of 82. The angular movement of the disc 13 and the number of times solenoids 30' will be energized will be as given in the explanation for an increase in the desired rate. Ordinarily it is indifierent how rapidly the disc 1-3 is rotated and the impulses transmitted to the solenoids 29 and 38', for no matter how rapidly the pointer or rate setter member 24 is shifted it is the motion of disc 8 that determines the rate of shift of the flow to the new value. However the motion of disc -73 may be used for a similar purpose without slow motion of 8 for by governing its rotation the interval between impulses may be made anything desired and so the time for a shift of How. It is desirable to make the teeth on ratchets 25 and 26 and the motion of pawls 25a and 26a small in such case so that eachincrement of flow will be small. By changing the position of disc I on disc I13 the speed of rotation may be altered so as to time the impulses for any desired rate of change of flow.

When it is desired to backwash a filter, the eiliuent valve as 4| is closed and remains closed until the filter is to be restored to service. It has been found desirable after a filter had been backwashed or the flow otherwise cut oil, to start thefllt-ration process at a slow and gradually accelerated rate until the desired rate of flow is at- I tained and thereafter to maintain this rate evenbridged. This breaks the circuit 01' coil A of motor 2| and of solenoid I04 and completes the circuit of coil B of motor 2| and the E. M. F. 85. The motor will therefore rotate in a clockwise direction and turn disc 8 in a counter-clockwise direction until further movement in this directionis limited by stop 2 5 on disc 8 meeting stationary stop 2I6. (The motor will then be stalled but the one employed is of a type not thereby injured.) In the meantime pointer 8 and associated contact 3| will move toward and to the zero scale position. The relative positions of stops 2I5 and 2I8 are such that when disc 8 can move no farther and the pointer 65 is at zero on the scaIe the contact 8| will rest on ring 32 thereby energizing solenoid 59 of valve 38, which closes the regulating valve 42. At the same time contact 34 rests on ring 86 but since the circuit of which these and coil A of motor 26 are a is broken at contacts H2 and M3, coil A is disconnected from the E. M. F. 65.

When the filter is to be put back into service the handle IIO-is moved to the open position, breaking the bridge between'contacts I I4 and I I5 and bridging contacts 2 and 3. This will start motor 2| in a counter-clockwise direction and energize solenoid I04 which will place clutch 8 in engagement with gear I2. The latter and also disc 8'will move in a clockwise direction. The electrical circuit established to accomplish this is as follows: From terminal SI of E. M. F. 65, conductor I60, contact 34, ring 36, conductor I52,v contacts 2 and H3, conductor 52a, coil A to terminal 63 ME. M. F. 65. 'Also from conductor 52a through conductor 104b, solenoid I04, conductor I04a, to terminal 63 of E. M. F. 65. When the neutral point between rings 35 and 36 reaches contact 34 motor 2| will stop, solenoid I84 will be de-energized and disc 8 will stop at the position corresponding to the rate of flow for which the pointer 24 is set.

When disc 8 started its motion away from the zero position, valve 42 was closed for the reason that contact 3| rested on ring 32. Because valve 42 was closed, pointer 6 and associated contact 3| did not move. However, because of the movement of disc 8, ring 32 moved from under contact 3| and contact 3| moved into ring 33. This caused the opening of valve 42, permitting a flow motion until ring 33 moves forward enough to.

again make contact with 3|, thus opening 5| and thereby increasing the opening of valve 42. This process is continued until the neutral zone between rings 35 and 36 reaches contact 34. It is evident then that the pointer 8 cannot reach the rate for which the apparatus is set in less than the predetermined time it takes disc 8 to travel from zero to the desired rate.

For purposes of illustration I have shown and described one form in which my invention may be embodied but of course many changes in details and form may be made without departing from the conception and teaching thereof. Such changes will no doubt occur to those skilled in the art and may in some instances or respects be of some advantage. The appended claims are accordingly to be given as broad a scope as the disclosure and the prior art warrant.

I claim:

1. A conduit for fluid flow, a flow controlling valve on said conduit, a member adapted to be positioned by and to indicate the flow through said conduit, a second member adapted to be posltioned according to flow desired through said conduit, means comprising a third movable member associated with said first two movable members whereby on motion of said indicative member beyond predetermined limits relative to the said third member said valve will be repositioned, and means whereby when said second member has been positioned to a new rate of flow said third member will be caused to move at a relatively slow rate to a corresponding new position. r

2. A conduit for fluid flow, a rate of flow controller that comprises a regulating valve on said tively associated with said conduit, to indicate the rate of flow therethrough, a rate setting member associated with said rate indicating member, means operatively joining said members and said valve whereby on relative motion of said indicating member or said setting member beyond predetermined limits said valve will be repositioned, said means including means whereby the repositioning of said valve will be caused to take place slowly when such repositioning follows motion of said setting member.

3. A conduit for fluid flow, a rate of flow controller comprising a valve on said conduit, a second valve on said conduit, a rate setting member operatively associated with said controller, operating means associated with said second valve to open and close same, means associated with said second valve whereby when said second valve is actuated to close, said rate controller is separated from said rate setter and the valve thereof caused to close and when said second valve is actuated to open the influence of the rate setter is restored, and intermediate means for limiting the speed with which the flow is restored to the full set value.

4. A conduit for fluid flow, a rate of flow controlling member comprising a valve on said conduit, rate setting means including a movable setting member associated with said controller for determining the allowed flow, a second valve on said conduit, operating means associated with said second valve for causing same to open and close, means associated with said operating means whereby when said second valve is actuated to close, said controller is separated from said rate setter and the valve thereof actuated to close and when said second valve is actuated to open the controller is restored to the influence of the rate -setter, a movable member coacting with and intermediate between said rate setting and rate controlling members and means whereby said intermediate member may be moved at a relatively slow predetermined rate so as to limit the rate of change of flow through the controlling member. I

5. A conduit for fluid flow, a rate of flow controlling member on said conduit, said member being biased to holdthe flow at a set rate, a movable setting member for fixing the flow value to which the controller is biased, means for shifting said setting member from a point relatively remote therefrom whereby to bias the controlling member to a new flow value and means whereby regardless of the rapidity of shift of the setting member the bias of the controlling member is shifted relatively slowly from the old value to the new.

6. A fluid flow system comprising a conduit, a how controlling member thereon, said member being biased to hold the flow at a set value, a rate of flow indicating member and a. rate setting member, an intermediate member operatively aS- sociated with both said indicating member and said setting member, means for shifting said rate setting member to determine a new flow value, and means efl'ective upon such shift to move said intermediate member at a relatively slow rate to a new position corresponding to that of the sett member.

7. The combination with a rate of flow controller of the type biased to hold a flow at a set value, of a movable rate setting member that may be quickly, moved to set to a new flow value, a second movable member whose rate of shift detenes the rapidity with which the flow may be altered from an old value to a new, and means for moving said second movable member at a predetermined speed.

8. In a fluid flow system, aconduit, a flow controller member comprising a valve on said conduit, 5 said controller being biased to hold the flow at a set rate, a movable rate setting member for said controller that may be quickly shifted to set to a new flow value, a movable member the position of which determines the bias of the controller member and means efiective on shift of the setting member to slowly move said movable member to a new position corresponding to the new set value whereby the flow permitted by the controller iscorrespondingly slowly altered to the 15 new value.

9. In a flow control system, a conduit for fluid flow, a flow controller on said conduit, said controller being biased to hold the flow at a set rate, a member whose position is indicative of the existing flow, a movable setting member cooperative to determine the rate to which the controller is biased, a movable member intermediate said indicative member and said setting member and cooperating with the first as to maintaining flow 25 at some set value and with the second to shift the flow to some new value,'and means rendered operative on shift of said setting member to a new position to move said intermediate member to a corresponding position. 30

10. The apparatus of claim 9 in which the movement of the intermediate member is at a predetermined relatively slow rate.

11. The apparatus of claim 9 in which the movement of the intermediate part is at a different rate when shifting for an increased -flow than when shiftingfor a decreased flow.

12. The apparatus of claim "9 wherein the means for moving the intermediate part may be altered so as to change the speed with which the intermediate part is moved. I

13. A plurality of conduits for fluid flow, a flow controller comprising a valve on each of said conduits, each of said controllers being biased to hold the flow therethrough at a set value, a member joined to each of said conduits in a manner such that its position is indicative of the flow therethrough, a setting member assoicated with each controller whose position is determinative of the value to which the flow 50 therethrough will be biased, a remote control station common to all said controllers, means at said station whereby impulses may be transmitted therefrom to shift said setting members, and means at each controller adapted to control the rate of change from one flow value to another.

14. The apparatus of claim 13 wherein there is at said remote station a setting member that may be shifted and wherein the degree of such shift determines the number of such impulses that will be transmitted.

15. A fluid flow system comprising a conduit,

a flow control member on said conduit, said control member being biased to hold the flowtherethrough at a set value, a shiftable setting mem-' her so joined to said control member that its a conduit for fluid flow, a flow controller comprising a regulating valve on said conduit, said controller being biased to normally hold the flow at a set value, a shut-oi! valve on said conduit,

- means associated with said shut-off valve for causing said regulating valve to move toward closed position when the shut-oil? valve is caused to close and to cause said regulating valve to open when said shut-oil valve is caused to open, and means whereby the opening motion of said regulating valve is impeded resultantly of too rapid increase of flow through said conduit.

1'7. A flow control system comprising in combination a conduit for fluid flow, a flow controller on said conduit, said controller being of the type that is biased tohold the flow ata set value, a movable member whose position is determinative as to the flow value to which said controller is biased, and means for moving said member at a slow rate from one position to another whereby the shift of flow from one value to another is correspondingly slow.

18. A conduit for fluid flow, a rate of flow controlling device on said conduit, said device being biased to hold the flow to a set rate, a movable setting member whereby the flow value to which the controller is biased may be altered, means for shifting said setting member, and means for controlling the rate of shift of the bias of the controlling device from an old value to a new,

irrespective of the rapidity of shift of the setting member. 

